Expanding the expression, we get:
(4a - b)(a - 6b) + a(25b - 3a)= 4a(a) - 4a(6b) - b(a) + b(6b) + 25ab - 3a^2= 4a^2 - 24ab - ab + 6b^2 + 25ab - 3a^2= 4a^2 - 3a^2 - 24ab + 25ab - ab + 6b^2= a^2 + ab + 6b^2
Expanding the expression, we get:
(4a - b)(a - 6b) + a(25b - 3a)
= 4a(a) - 4a(6b) - b(a) + b(6b) + 25ab - 3a^2
= 4a^2 - 24ab - ab + 6b^2 + 25ab - 3a^2
= 4a^2 - 3a^2 - 24ab + 25ab - ab + 6b^2
= a^2 + ab + 6b^2